1 | #include <stdio.h> |
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2 | #include <assert.h> |
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3 | #include <stdlib.h> |
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4 | |
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5 | #define SHOW(x, fmt) printf( #x ": " fmt "\n", x ) |
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6 | |
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7 | #ifdef ERRS |
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8 | #define ERR(...) __VA_ARGS__ |
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9 | #else |
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10 | #define ERR(...) |
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11 | #endif |
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12 | |
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13 | |
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14 | |
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15 | int main() { |
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16 | |
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17 | /* |
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18 | As in the last section, we inspect the declaration ... |
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19 | */ |
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20 | float a[3][10]; |
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21 | /* |
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22 | |
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23 | */ |
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24 | static_assert(sizeof(float)==4); // floats (atomic elements) are 4 bytes |
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25 | static_assert(sizeof(void*)==8); // pointers are 8 bytes |
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26 | /* |
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27 | |
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28 | The significant axis of deriving expressions from @a@ is now ``itself,'' ``first element'' or ``first grand-element (meaning, first element of first element).'' |
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29 | */ |
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30 | static_assert(sizeof( a ) == 120); // the array, float[3][10] |
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31 | static_assert(sizeof( a[0] ) == 40 ); // its first element, float[10] |
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32 | static_assert(sizeof( a[0][0] ) == 4 ); // its first grand element, float |
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33 | |
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34 | static_assert(sizeof(&(a )) == 8 ); // pointer to the array, float(*)[3][10] |
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35 | static_assert(sizeof(&(a[0] )) == 8 ); // pointer to its first element, float(*)[10] |
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36 | static_assert(sizeof(&(a[0][0])) == 8 ); // pointer to its first grand-element, float* |
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37 | |
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38 | float (*pa )[3][10] = &(a ); |
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39 | float (*pa0 ) [10] = &(a[0] ); |
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40 | float *pa00 = &(a[0][0]); |
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41 | |
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42 | static_assert((void*)&a == (void*)&(a[0] )); |
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43 | static_assert((void*)&a == (void*)&(a[0][0])); |
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44 | |
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45 | assert( (void *) pa == (void *) pa0 ); |
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46 | assert( (void *) pa == (void *) pa00 ); |
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47 | |
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48 | // float (*b[3])[10]; |
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49 | float *b[3]; |
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50 | for (int i = 0; i < 3; i ++) { |
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51 | b[i] = malloc(sizeof(float[10])); |
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52 | } |
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53 | a[2][3]; |
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54 | b[2][3]; |
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55 | /* |
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56 | |
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57 | */ |
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58 | |
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59 | } |
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